Usefulness of Simultaneous Evaluations of Contractile Reserve, Perfusion, and Metabolism During Dobutamine Stress for Predicting Wall Motion Reversibility (Myocardial Stunning) After Successful PTCA

The optimal diagnostic approaches using contractile reserve, perfusion, and free fatty acid metabolism together for identifying myocardial stunning after reperfusion have not been clarified in the clinical setting. We investigated the usefulness of simultaneous evaluation of these parameters during myocardial stunning to predict the functional recovery in infarct-related myocardium after reperfusion. In 43 patients (60.7 +/- 10.4 years) with successful coronary angioplasty early after a first myocardial infarction, low-dose (5 to 10 microg/kg/min) dobutamine stress thallium-201/iodine-123 beta-methyl-iodophenyl pentadecanoic acid (BMIPP) dual-isotope single photon emission computed tomography was performed with echocardiography in the acute phase within 1 week after reperfusion. Regional wall motion and the uptake of each tracer were obtained simultaneously in the infarct-related segments. In 93 segments with dyssynergy in the acute phase after reperfusion, the sensitivity, specificity, and accuracy using contractile reserve for predicting the final functional recovery in the chronic phase more than 3 months after PTCA were 81.3%, 67.2%, and 72%, respectively. More accurate predictions were obtained by simultaneous measurements of thallium-201 and BMIPP uptakes (93.8%, 66.7%, and 79.4%, respectively). The final functional recovery in the stunned myocardium after early reperfusion following acute myocardial infarction was predicted more accurately by simultaneous evaluation of these parameters at dobutamine stress testing.